// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading

#include "content/child/resource_dispatcher.h"

#include <utility>

#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/debug/alias.h"
#include "base/debug/dump_without_crashing.h"
#include "base/debug/stack_trace.h"
#include "base/feature_list.h"
#include "base/files/file_path.h"
#include "base/memory/ptr_util.h"
#include "base/memory/shared_memory.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram_macros.h"
#include "base/rand_util.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
#include "content/child/request_extra_data.h"
#include "content/child/resource_scheduling_filter.h"
#include "content/child/shared_memory_received_data_factory.h"
#include "content/child/site_isolation_stats_gatherer.h"
#include "content/child/sync_load_response.h"
#include "content/child/url_loader_client_impl.h"
#include "content/common/inter_process_time_ticks_converter.h"
#include "content/common/navigation_params.h"
#include "content/common/resource_messages.h"
#include "content/common/resource_request.h"
#include "content/common/resource_request_completion_status.h"
#include "content/public/child/fixed_received_data.h"
#include "content/public/child/request_peer.h"
#include "content/public/child/resource_dispatcher_delegate.h"
#include "content/public/common/content_features.h"
#include "content/public/common/resource_response.h"
#include "content/public/common/resource_type.h"
#include "mojo/public/cpp/bindings/associated_group.h"
#include "net/base/net_errors.h"
#include "net/base/request_priority.h"
#include "net/http/http_response_headers.h"

namespace content {

namespace {

    // Converts |time| from a remote to local TimeTicks, overwriting the original
    // value.
    void RemoteToLocalTimeTicks(
        const InterProcessTimeTicksConverter& converter,
        base::TimeTicks* time)
    {
        RemoteTimeTicks remote_time = RemoteTimeTicks::FromTimeTicks(*time);
        *time = converter.ToLocalTimeTicks(remote_time).ToTimeTicks();
    }

    void CrashOnMapFailure()
    {
#if defined(OS_WIN)
        DWORD last_err = GetLastError();
        base::debug::Alias(&last_err);
#endif
        CHECK(false);
    }

    // Each resource request is assigned an ID scoped to this process.
    int MakeRequestID()
    {
        // NOTE: The resource_dispatcher_host also needs probably unique
        // request_ids, so they count down from -2 (-1 is a special we're
        // screwed value), while the renderer process counts up.
        static int next_request_id = 0;
        return next_request_id++;
    }

    void CheckSchemeForReferrerPolicy(const ResourceRequest& request)
    {
        if ((request.referrer_policy == blink::WebReferrerPolicyDefault || request.referrer_policy == blink::WebReferrerPolicyNoReferrerWhenDowngrade) && request.referrer.SchemeIsCryptographic() && !request.url.SchemeIsCryptographic()) {
            LOG(FATAL) << "Trying to send secure referrer for insecure request "
                       << "without an appropriate referrer policy.\n"
                       << "URL = " << request.url << "\n"
                       << "Referrer = " << request.referrer;
        }
    }

} // namespace

ResourceDispatcher::ResourceDispatcher(
    IPC::Sender* sender,
    scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner)
    : message_sender_(sender)
    , delegate_(NULL)
    , io_timestamp_(base::TimeTicks())
    , main_thread_task_runner_(main_thread_task_runner)
    , weak_factory_(this)
{
}

ResourceDispatcher::~ResourceDispatcher()
{
}

bool ResourceDispatcher::OnMessageReceived(const IPC::Message& message)
{
    if (!IsResourceDispatcherMessage(message)) {
        return false;
    }

    int request_id;

    base::PickleIterator iter(message);
    if (!iter.ReadInt(&request_id)) {
        NOTREACHED() << "malformed resource message";
        return true;
    }

    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info) {
        // Release resources in the message if it is a data message.
        ReleaseResourcesInDataMessage(message);
        return true;
    }

    if (request_info->is_deferred) {
        request_info->deferred_message_queue.push_back(new IPC::Message(message));
        return true;
    }

    // Make sure any deferred messages are dispatched before we dispatch more.
    if (!request_info->deferred_message_queue.empty()) {
        request_info->deferred_message_queue.push_back(new IPC::Message(message));
        FlushDeferredMessages(request_id);
        return true;
    }

    DispatchMessage(message);
    return true;
}

ResourceDispatcher::PendingRequestInfo*
ResourceDispatcher::GetPendingRequestInfo(int request_id)
{
    PendingRequestMap::iterator it = pending_requests_.find(request_id);
    if (it == pending_requests_.end()) {
        // This might happen for kill()ed requests on the webkit end.
        return NULL;
    }
    return it->second.get();
}

void ResourceDispatcher::OnUploadProgress(int request_id,
    int64_t position,
    int64_t size)
{
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;

    request_info->peer->OnUploadProgress(position, size);

    // Acknowledge receipt
    message_sender_->Send(new ResourceHostMsg_UploadProgress_ACK(request_id));
}

void ResourceDispatcher::OnReceivedResponse(
    int request_id, const ResourceResponseHead& response_head)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedResponse");
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;
    request_info->response_start = ConsumeIOTimestamp();

    if (delegate_) {
        std::unique_ptr<RequestPeer> new_peer = delegate_->OnReceivedResponse(
            std::move(request_info->peer), response_head.mime_type,
            request_info->url);
        DCHECK(new_peer);
        request_info->peer = std::move(new_peer);
    }

    ResourceResponseInfo renderer_response_info;
    ToResourceResponseInfo(*request_info, response_head, &renderer_response_info);
    request_info->site_isolation_metadata = SiteIsolationStatsGatherer::OnReceivedResponse(
        request_info->frame_origin, request_info->response_url,
        request_info->resource_type, request_info->origin_pid,
        renderer_response_info);
    request_info->peer->OnReceivedResponse(renderer_response_info);
}

void ResourceDispatcher::OnReceivedCachedMetadata(
    int request_id, const std::vector<char>& data)
{
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;

    if (data.size())
        request_info->peer->OnReceivedCachedMetadata(&data.front(), data.size());
}

void ResourceDispatcher::OnSetDataBuffer(int request_id,
    base::SharedMemoryHandle shm_handle,
    int shm_size,
    base::ProcessId renderer_pid)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnSetDataBuffer");
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;

    bool shm_valid = base::SharedMemory::IsHandleValid(shm_handle);
    CHECK((shm_valid && shm_size > 0) || (!shm_valid && !shm_size));

    request_info->buffer.reset(
        new base::SharedMemory(shm_handle, true)); // read only
    request_info->received_data_factory = make_scoped_refptr(new SharedMemoryReceivedDataFactory(
        message_sender_, request_id, request_info->buffer));

    bool ok = request_info->buffer->Map(shm_size);
    if (!ok) {
        // Added to help debug crbug/160401.
        base::ProcessId renderer_pid_copy = renderer_pid;
        base::debug::Alias(&renderer_pid_copy);

        base::SharedMemoryHandle shm_handle_copy = shm_handle;
        base::debug::Alias(&shm_handle_copy);

        CrashOnMapFailure();
        return;
    }

    // TODO(erikchen): Temporary debugging. http://crbug.com/527588.
    CHECK_GE(shm_size, 0);
    CHECK_LE(shm_size, 512 * 1024);
    request_info->buffer_size = shm_size;
}

void ResourceDispatcher::OnReceivedInlinedDataChunk(
    int request_id,
    const std::vector<char>& data,
    int encoded_data_length)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedInlinedDataChunk");
    DCHECK(!data.empty());
    DCHECK(base::FeatureList::IsEnabled(
        features::kOptimizeLoadingIPCForSmallResources));

    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info || data.empty())
        return;

    // Check whether this response data is compliant with our cross-site
    // document blocking policy. We only do this for the first chunk of data.
    if (request_info->site_isolation_metadata.get()) {
        SiteIsolationStatsGatherer::OnReceivedFirstChunk(
            request_info->site_isolation_metadata, data.data(), data.size());
        request_info->site_isolation_metadata.reset();
    }

    DCHECK(!request_info->buffer.get());

    request_info->peer->OnReceivedData(
        base::MakeUnique<content::FixedReceivedData>(data));

    // Get the request info again as the client callback may modify the info.
    request_info = GetPendingRequestInfo(request_id);
    if (request_info && encoded_data_length > 0)
        request_info->peer->OnTransferSizeUpdated(encoded_data_length);
}

void ResourceDispatcher::OnReceivedData(int request_id,
    int data_offset,
    int data_length,
    int encoded_data_length)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedData");
    DCHECK_GT(data_length, 0);
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    bool send_ack = true;
    if (request_info && data_length > 0) {
        CHECK(base::SharedMemory::IsHandleValid(request_info->buffer->handle()));
        CHECK_GE(request_info->buffer_size, data_offset + data_length);

        const char* data_start = static_cast<char*>(request_info->buffer->memory());
        CHECK(data_start);
        CHECK(data_start + data_offset);
        const char* data_ptr = data_start + data_offset;

        // Check whether this response data is compliant with our cross-site
        // document blocking policy. We only do this for the first chunk of data.
        if (request_info->site_isolation_metadata.get()) {
            SiteIsolationStatsGatherer::OnReceivedFirstChunk(
                request_info->site_isolation_metadata, data_ptr, data_length);
            request_info->site_isolation_metadata.reset();
        }

        std::unique_ptr<RequestPeer::ReceivedData> data = request_info->received_data_factory->Create(data_offset, data_length);
        // |data| takes care of ACKing.
        send_ack = false;
        request_info->peer->OnReceivedData(std::move(data));
    }

    // Get the request info again as the client callback may modify the info.
    request_info = GetPendingRequestInfo(request_id);
    if (request_info && encoded_data_length > 0)
        request_info->peer->OnTransferSizeUpdated(encoded_data_length);

    // Acknowledge the reception of this data.
    if (send_ack)
        message_sender_->Send(new ResourceHostMsg_DataReceived_ACK(request_id));
}

void ResourceDispatcher::OnDownloadedData(int request_id,
    int data_len,
    int encoded_data_length)
{
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;

    request_info->peer->OnDownloadedData(data_len, encoded_data_length);
}

void ResourceDispatcher::OnReceivedRedirect(
    int request_id,
    const net::RedirectInfo& redirect_info,
    const ResourceResponseHead& response_head)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedRedirect");
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;
    request_info->response_start = ConsumeIOTimestamp();

    ResourceResponseInfo renderer_response_info;
    ToResourceResponseInfo(*request_info, response_head, &renderer_response_info);
    if (request_info->peer->OnReceivedRedirect(redirect_info,
            renderer_response_info)) {
        // Double-check if the request is still around. The call above could
        // potentially remove it.
        request_info = GetPendingRequestInfo(request_id);
        if (!request_info)
            return;
        // We update the response_url here so that we can send it to
        // SiteIsolationStatsGatherer later when OnReceivedResponse is called.
        request_info->response_url = redirect_info.new_url;
        request_info->pending_redirect_message.reset(
            new ResourceHostMsg_FollowRedirect(request_id));
        if (!request_info->is_deferred) {
            FollowPendingRedirect(request_id, request_info);
        }
    } else {
        Cancel(request_id);
    }
}

void ResourceDispatcher::FollowPendingRedirect(
    int request_id,
    PendingRequestInfo* request_info)
{
    IPC::Message* msg = request_info->pending_redirect_message.release();
    if (msg) {
        if (request_info->url_loader) {
            request_info->url_loader->FollowRedirect();
            delete msg;
        } else {
            message_sender_->Send(msg);
        }
    }
}

void ResourceDispatcher::OnRequestComplete(
    int request_id,
    const ResourceRequestCompletionStatus& request_complete_data)
{
    TRACE_EVENT0("loader", "ResourceDispatcher::OnRequestComplete");

    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;
    request_info->completion_time = ConsumeIOTimestamp();
    request_info->buffer.reset();
    if (request_info->received_data_factory)
        request_info->received_data_factory->Stop();
    request_info->received_data_factory = nullptr;
    request_info->buffer_size = 0;

    RequestPeer* peer = request_info->peer.get();

    if (delegate_) {
        std::unique_ptr<RequestPeer> new_peer = delegate_->OnRequestComplete(
            std::move(request_info->peer), request_info->resource_type,
            request_complete_data.error_code);
        DCHECK(new_peer);
        request_info->peer = std::move(new_peer);
    }

    base::TimeTicks renderer_completion_time = ToRendererCompletionTime(
        *request_info, request_complete_data.completion_time);

    // The request ID will be removed from our pending list in the destructor.
    // Normally, dispatching this message causes the reference-counted request to
    // die immediately.
    // TODO(kinuko): Revisit here. This probably needs to call request_info->peer
    // but the past attempt to change it seems to have caused crashes.
    // (crbug.com/547047)
    peer->OnCompletedRequest(request_complete_data.error_code,
        request_complete_data.was_ignored_by_handler,
        request_complete_data.exists_in_cache,
        renderer_completion_time,
        request_complete_data.encoded_data_length,
        request_complete_data.encoded_body_length);
}

bool ResourceDispatcher::RemovePendingRequest(int request_id)
{
    PendingRequestMap::iterator it = pending_requests_.find(request_id);
    if (it == pending_requests_.end())
        return false;

    PendingRequestInfo* request_info = it->second.get();

    bool release_downloaded_file = request_info->download_to_file;

    ReleaseResourcesInMessageQueue(&request_info->deferred_message_queue);

    // Cancel loading.
    it->second->url_loader = nullptr;
    // Clear URLLoaderClient to stop receiving further Mojo IPC from the browser
    // process.
    it->second->url_loader_client = nullptr;

    // Always delete the pending_request asyncly so that cancelling the request
    // doesn't delete the request context info while its response is still being
    // handled.
    main_thread_task_runner_->DeleteSoon(FROM_HERE, it->second.release());
    pending_requests_.erase(it);

    if (release_downloaded_file) {
        message_sender_->Send(
            new ResourceHostMsg_ReleaseDownloadedFile(request_id));
    }

    if (resource_scheduling_filter_.get())
        resource_scheduling_filter_->ClearRequestIdTaskRunner(request_id);

    return true;
}

void ResourceDispatcher::Cancel(int request_id)
{
    PendingRequestMap::iterator it = pending_requests_.find(request_id);
    if (it == pending_requests_.end()) {
        DVLOG(1) << "unknown request";
        return;
    }

    // |completion_time.is_null()| is a proxy for OnRequestComplete never being
    // called.
    // TODO(csharrison): Remove this code when crbug.com/557430 is resolved.
    // Sample this enough that this won't dump much more than a hundred times a
    // day even without the static guard. The guard ensures this dumps much less
    // frequently, because these aborts frequently come in quick succession.
    const PendingRequestInfo& info = *it->second;
    int64_t request_time = (base::TimeTicks::Now() - info.request_start).InMilliseconds();
    if (info.resource_type == ResourceType::RESOURCE_TYPE_MAIN_FRAME && info.completion_time.is_null() && request_time < 100 && base::RandDouble() < .000001) {
        static bool should_dump = true;
        if (should_dump) {
            char url_copy[256] = { 0 };
            strncpy(url_copy, info.response_url.spec().c_str(),
                sizeof(url_copy));
            base::debug::Alias(&url_copy);
            base::debug::Alias(&request_time);
            base::debug::DumpWithoutCrashing();
            should_dump = false;
        }
    }
    // Cancel the request if it didn't complete, and clean it up so the bridge
    // will receive no more messages.
    if (info.completion_time.is_null() && !info.url_loader)
        message_sender_->Send(new ResourceHostMsg_CancelRequest(request_id));
    RemovePendingRequest(request_id);
}

void ResourceDispatcher::SetDefersLoading(int request_id, bool value)
{
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info) {
        DLOG(ERROR) << "unknown request";
        return;
    }
    if (value) {
        request_info->is_deferred = value;
        if (request_info->url_loader_client)
            request_info->url_loader_client->SetDefersLoading();
    } else if (request_info->is_deferred) {
        request_info->is_deferred = false;

        if (request_info->url_loader_client)
            request_info->url_loader_client->UnsetDefersLoading();

        FollowPendingRedirect(request_id, request_info);

        main_thread_task_runner_->PostTask(
            FROM_HERE, base::Bind(&ResourceDispatcher::FlushDeferredMessages, weak_factory_.GetWeakPtr(), request_id));
    }
}

void ResourceDispatcher::DidChangePriority(int request_id,
    net::RequestPriority new_priority,
    int intra_priority_value)
{
    DCHECK(base::ContainsKey(pending_requests_, request_id));
    message_sender_->Send(new ResourceHostMsg_DidChangePriority(
        request_id, new_priority, intra_priority_value));
}

void ResourceDispatcher::OnTransferSizeUpdated(int request_id,
    int32_t transfer_size_diff)
{
    DCHECK_GT(transfer_size_diff, 0);
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
        return;

    // TODO(yhirano): Consider using int64_t in
    // RequestPeer::OnTransferSizeUpdated.
    request_info->peer->OnTransferSizeUpdated(transfer_size_diff);
}

ResourceDispatcher::PendingRequestInfo::PendingRequestInfo(
    std::unique_ptr<RequestPeer> peer,
    ResourceType resource_type,
    int origin_pid,
    const url::Origin& frame_origin,
    const GURL& request_url,
    bool download_to_file)
    : peer(std::move(peer))
    , resource_type(resource_type)
    , origin_pid(origin_pid)
    , url(request_url)
    , frame_origin(frame_origin)
    , response_url(request_url)
    , download_to_file(download_to_file)
    , request_start(base::TimeTicks::Now())
{
}

ResourceDispatcher::PendingRequestInfo::~PendingRequestInfo()
{
}

void ResourceDispatcher::DispatchMessage(const IPC::Message& message)
{
    IPC_BEGIN_MESSAGE_MAP(ResourceDispatcher, message)
    IPC_MESSAGE_HANDLER(ResourceMsg_UploadProgress, OnUploadProgress)
    IPC_MESSAGE_HANDLER(ResourceMsg_ReceivedResponse, OnReceivedResponse)
    IPC_MESSAGE_HANDLER(ResourceMsg_ReceivedCachedMetadata,
        OnReceivedCachedMetadata)
    IPC_MESSAGE_HANDLER(ResourceMsg_ReceivedRedirect, OnReceivedRedirect)
    IPC_MESSAGE_HANDLER(ResourceMsg_SetDataBuffer, OnSetDataBuffer)
    IPC_MESSAGE_HANDLER(ResourceMsg_InlinedDataChunkReceived,
        OnReceivedInlinedDataChunk)
    IPC_MESSAGE_HANDLER(ResourceMsg_DataReceived, OnReceivedData)
    IPC_MESSAGE_HANDLER(ResourceMsg_DataDownloaded, OnDownloadedData)
    IPC_MESSAGE_HANDLER(ResourceMsg_RequestComplete, OnRequestComplete)
    IPC_END_MESSAGE_MAP()
}

void ResourceDispatcher::FlushDeferredMessages(int request_id)
{
    PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
    if (!request_info || request_info->is_deferred)
        return;

    if (request_info->url_loader) {
        DCHECK(request_info->deferred_message_queue.empty());
        request_info->url_loader_client->FlushDeferredMessages();
        return;
    }

    // Because message handlers could result in request_info being destroyed,
    // we need to work with a stack reference to the deferred queue.
    MessageQueue q;
    q.swap(request_info->deferred_message_queue);
    while (!q.empty()) {
        IPC::Message* m = q.front();
        q.pop_front();
        DispatchMessage(*m);
        delete m;
        // We need to find the request again in the list as it may have completed
        // by now and the request_info instance above may be invalid.
        request_info = GetPendingRequestInfo(request_id);
        if (!request_info) {
            // The recipient is gone, the messages won't be handled and
            // resources they might hold won't be released. Explicitly release
            // them from here so that they won't leak.
            ReleaseResourcesInMessageQueue(&q);
            return;
        }
        // If this request is deferred in the context of the above message, then
        // we should honor the same and stop dispatching further messages.
        if (request_info->is_deferred) {
            request_info->deferred_message_queue.swap(q);
            return;
        }
    }
}

void ResourceDispatcher::StartSync(
    std::unique_ptr<ResourceRequest> request,
    int routing_id,
    SyncLoadResponse* response,
    blink::WebURLRequest::LoadingIPCType ipc_type,
    mojom::URLLoaderFactory* url_loader_factory)
{
    CheckSchemeForReferrerPolicy(*request);

    SyncLoadResult result;

    if (ipc_type == blink::WebURLRequest::LoadingIPCType::Mojo) {
        if (!url_loader_factory->SyncLoad(
                routing_id, MakeRequestID(), *request, &result)) {
            response->error_code = net::ERR_FAILED;
            return;
        }
    } else {
        IPC::SyncMessage* msg = new ResourceHostMsg_SyncLoad(
            routing_id, MakeRequestID(), *request, &result);

        // NOTE: This may pump events (see RenderThread::Send).
        if (!message_sender_->Send(msg)) {
            response->error_code = net::ERR_FAILED;
            return;
        }
    }

    response->error_code = result.error_code;
    response->url = result.final_url;
    response->headers = result.headers;
    response->mime_type = result.mime_type;
    response->charset = result.charset;
    response->request_time = result.request_time;
    response->response_time = result.response_time;
    response->load_timing = result.load_timing;
    response->devtools_info = result.devtools_info;
    response->data.swap(result.data);
    response->download_file_path = result.download_file_path;
    response->socket_address = result.socket_address;
    response->encoded_data_length = result.encoded_data_length;
    response->encoded_body_length = result.encoded_body_length;
}

int ResourceDispatcher::StartAsync(
    std::unique_ptr<ResourceRequest> request,
    int routing_id,
    scoped_refptr<base::SingleThreadTaskRunner> loading_task_runner,
    const url::Origin& frame_origin,
    std::unique_ptr<RequestPeer> peer,
    blink::WebURLRequest::LoadingIPCType ipc_type,
    mojom::URLLoaderFactory* url_loader_factory,
    mojo::AssociatedGroup* associated_group)
{
    CheckSchemeForReferrerPolicy(*request);

    // Compute a unique request_id for this renderer process.
    int request_id = MakeRequestID();
    pending_requests_[request_id] = base::MakeUnique<PendingRequestInfo>(
        std::move(peer), request->resource_type, request->origin_pid,
        frame_origin, request->url, request->download_to_file);

    if (resource_scheduling_filter_.get() && loading_task_runner) {
        resource_scheduling_filter_->SetRequestIdTaskRunner(request_id,
            loading_task_runner);
    }

    if (ipc_type == blink::WebURLRequest::LoadingIPCType::Mojo) {
        std::unique_ptr<URLLoaderClientImpl> client(
            new URLLoaderClientImpl(request_id, this, main_thread_task_runner_));
        mojom::URLLoaderAssociatedPtr url_loader;
        mojom::URLLoaderClientAssociatedPtrInfo client_ptr_info;
        client->Bind(&client_ptr_info, associated_group);
        url_loader_factory->CreateLoaderAndStart(
            MakeRequest(&url_loader, associated_group), routing_id, request_id,
            *request, std::move(client_ptr_info));
        pending_requests_[request_id]->url_loader = std::move(url_loader);
        pending_requests_[request_id]->url_loader_client = std::move(client);
    } else {
        message_sender_->Send(
            new ResourceHostMsg_RequestResource(routing_id, request_id, *request));
    }

    return request_id;
}

void ResourceDispatcher::ToResourceResponseInfo(
    const PendingRequestInfo& request_info,
    const ResourceResponseHead& browser_info,
    ResourceResponseInfo* renderer_info) const
{
    *renderer_info = browser_info;
    if (base::TimeTicks::IsConsistentAcrossProcesses() || request_info.request_start.is_null() || request_info.response_start.is_null() || browser_info.request_start.is_null() || browser_info.response_start.is_null() || browser_info.load_timing.request_start.is_null()) {
        return;
    }
    InterProcessTimeTicksConverter converter(
        LocalTimeTicks::FromTimeTicks(request_info.request_start),
        LocalTimeTicks::FromTimeTicks(request_info.response_start),
        RemoteTimeTicks::FromTimeTicks(browser_info.request_start),
        RemoteTimeTicks::FromTimeTicks(browser_info.response_start));

    net::LoadTimingInfo* load_timing = &renderer_info->load_timing;
    RemoteToLocalTimeTicks(converter, &load_timing->request_start);
    RemoteToLocalTimeTicks(converter, &load_timing->proxy_resolve_start);
    RemoteToLocalTimeTicks(converter, &load_timing->proxy_resolve_end);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_start);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_end);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_start);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_end);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_start);
    RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_end);
    RemoteToLocalTimeTicks(converter, &load_timing->send_start);
    RemoteToLocalTimeTicks(converter, &load_timing->send_end);
    RemoteToLocalTimeTicks(converter, &load_timing->receive_headers_end);
    RemoteToLocalTimeTicks(converter, &load_timing->push_start);
    RemoteToLocalTimeTicks(converter, &load_timing->push_end);
    RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_start_time);
    RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_ready_time);

    // Collect UMA on the inter-process skew.
    bool is_skew_additive = false;
    if (converter.IsSkewAdditiveForMetrics()) {
        is_skew_additive = true;
        base::TimeDelta skew = converter.GetSkewForMetrics();
        if (skew >= base::TimeDelta()) {
            UMA_HISTOGRAM_TIMES(
                "InterProcessTimeTicks.BrowserAhead_BrowserToRenderer", skew);
        } else {
            UMA_HISTOGRAM_TIMES(
                "InterProcessTimeTicks.BrowserBehind_BrowserToRenderer", -skew);
        }
    }
    UMA_HISTOGRAM_BOOLEAN(
        "InterProcessTimeTicks.IsSkewAdditive_BrowserToRenderer",
        is_skew_additive);
}

base::TimeTicks ResourceDispatcher::ToRendererCompletionTime(
    const PendingRequestInfo& request_info,
    const base::TimeTicks& browser_completion_time) const
{
    if (request_info.completion_time.is_null()) {
        return browser_completion_time;
    }

    // TODO(simonjam): The optimal lower bound should be the most recent value of
    // TimeTicks::Now() returned to WebKit. Is it worth trying to cache that?
    // Until then, |response_start| is used as it is the most recent value
    // returned for this request.
    int64_t result = std::max(browser_completion_time.ToInternalValue(),
        request_info.response_start.ToInternalValue());
    result = std::min(result, request_info.completion_time.ToInternalValue());
    return base::TimeTicks::FromInternalValue(result);
}

base::TimeTicks ResourceDispatcher::ConsumeIOTimestamp()
{
    if (io_timestamp_ == base::TimeTicks())
        return base::TimeTicks::Now();
    base::TimeTicks result = io_timestamp_;
    io_timestamp_ = base::TimeTicks();
    return result;
}

// static
bool ResourceDispatcher::IsResourceDispatcherMessage(
    const IPC::Message& message)
{
    switch (message.type()) {
    case ResourceMsg_UploadProgress::ID:
    case ResourceMsg_ReceivedResponse::ID:
    case ResourceMsg_ReceivedCachedMetadata::ID:
    case ResourceMsg_ReceivedRedirect::ID:
    case ResourceMsg_SetDataBuffer::ID:
    case ResourceMsg_InlinedDataChunkReceived::ID:
    case ResourceMsg_DataReceived::ID:
    case ResourceMsg_DataDownloaded::ID:
    case ResourceMsg_RequestComplete::ID:
        return true;

    default:
        break;
    }

    return false;
}

// static
void ResourceDispatcher::ReleaseResourcesInDataMessage(
    const IPC::Message& message)
{
    base::PickleIterator iter(message);
    int request_id;
    if (!iter.ReadInt(&request_id)) {
        NOTREACHED() << "malformed resource message";
        return;
    }

    // If the message contains a shared memory handle, we should close the handle
    // or there will be a memory leak.
    if (message.type() == ResourceMsg_SetDataBuffer::ID) {
        base::SharedMemoryHandle shm_handle;
        if (IPC::ParamTraits<base::SharedMemoryHandle>::Read(&message,
                &iter,
                &shm_handle)) {
            if (base::SharedMemory::IsHandleValid(shm_handle))
                base::SharedMemory::CloseHandle(shm_handle);
        }
    }
}

// static
void ResourceDispatcher::ReleaseResourcesInMessageQueue(MessageQueue* queue)
{
    while (!queue->empty()) {
        IPC::Message* message = queue->front();
        ReleaseResourcesInDataMessage(*message);
        queue->pop_front();
        delete message;
    }
}

void ResourceDispatcher::SetResourceSchedulingFilter(
    scoped_refptr<ResourceSchedulingFilter> resource_scheduling_filter)
{
    resource_scheduling_filter_ = resource_scheduling_filter;
}

} // namespace content
